Safety stop for bag closing machines



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ATTORNE Patented June 2, 1936 PATENT OFFICE SAFETY STOP FOR BAG CLOSINGMACHINES Howland F. Briggs, Buffalo, N. Y., assignor to Bagpak, Inc.,New York, N. Y., a corporation of Delaware Application September 13,1935, Serial No. 40,363

2 Claims.

The present invention relates to bag closing machines for filled openmouth paper bags. Although capable of general utility, the device isparticularly designed for use in connection with machines such asdisclosed and claimed in my co-pending application Serial No. 19,396,filed May 2, 1935, in which machines large multi-ply, paper bags arefilled with material and progressed through a sewing machine forstitching the open mouths. The device is not limited to such use, butmay be used in connection with any closure effecting means having meansfor gripping the collapsed mouth of a filled bag below the end thereofand assisting to feed the same while being closed.

An object of the present invention is to make possible the high speedproduction of filled and closed bags by automatically safeguardingagainst the presentation of improperly collapsed bag mouths to theclosing means. It sometimes happens that the plies of a bag becomefolded or disarranged in the bag gripping and feeding mechanism,necessitating careful supervision. If allowed to continue in suchfashion a poor closure will be formed, or the closing means will bedamaged. The latter is particularly true of a sewing machine, theneedles and other parts of which are broken very easily; The speed ofthe machine is thus affected by the necessity of inspecting each bagmouth before it reaches the closing means. The present inventioncorrects this defect by the provision of means for sensing the presenceof a defective bag mouth and stopping the machine prior to the entry ofthe same into the closing means. The operator thereby need only attendthat portion of the machine when and if an improperly arranged bag ispresented thereto.

In particular the invention comprises a plate having a bag mouthreceiving throat positioned above the path of the bags. As illustrated,the bags are gripped by chains or belts above which the ends of the bagsproject, and which assist to feed the bags into means for effecting theclosure of the projecting ends. A switch or switches are opened by thepivoting of said plate in case a bag mouth is disarranged and incapableof passing through the throat.

Referring to the drawing wherein like numerals refer to like partsthroughout:

Fig. 1 is a side elevation of the invention;

Fig. 2 is a plan view thereof;

Fig. 3 is an enlarged end elevation thereof; and

Fig. 4 is an enlarged cross-sectional view taken on line 44 of Fig. 1.

The illustrations show the device mounted upon a frame member 26 of themachine. A bag gripping and feeding belt 2|, supported on member 26,cooperates with an opposed belt 22 supported on a frame member 23. A bagmouth A is gripped between the belts below its end and presented therebyto any suitable operating means. The bags may be presented theretoautomatically, as in said aforementioned application, or manually. Thefeeding means need not comprise belts, as long as the bag mouth projectsas aforesaid. A standard comprising plates 24 and 25 rotatably supportsa rod 26, which is longitudinally fixed by means of collars 21. One endof rod 26 passes into an outlet box 28 and supports a switch 29 (orswitches as shown) for controlling the machine. The switches arepreferably of the mercury contact type, as illustrated. Rotation of rod26 from its normal angular position opens the circuit to the drivingmotors (not shown).

The other end of rod 26 projects over the path of the bags and carries afreely mounted plate 3|], prevented from slipping along the rod bycollars 3| and 32. The lower portion of plate 36 is provided with athroat 33 of such width that normal bag mouths may freely pass throughthe same. A pair of flaring guides 34 and 35 align the oncoming bagswith the throat. An abutting finger 36 fixed to collar 3| contacts theface of plate 36 which is held against the finger by a spring 31fastened to plate 30 and the end of an arm 38 fixed to collar 32. Plate30 normally hangs in substantially vertical position, but an improperbag mouth will rotate plate 36, rotating rod 26 by reason of spring 31and throwing the switches to open position. A limiting means is providedby means of a collar 40 fixed to rod 26 and carrying a lever 4|, to theend of which is attached a spring 42 extending to a pin 43 upon the faceof plate 24. Spring 42 is under no tension when plate 30 is verticallydisposed, whereas spring 31 is always under tension, and a folded bagmouth such as shown in Fig. 4 will cause rotation of the plate and roduntil spring 42 is placed under greater tension than spring 31. As soonas this occurs the plate may continue to rotate, but such rotation willbe relative to the rod and will not be of any great extent due to theopening of switch 29. In this manner breakage of switch parts isprevented.

Fig. 4 illustrates the manner in which one corner of a gusset may becomefolded back, causing the device to operate.

This is the most frequent cause of trouble, but other faults occur suchas breakage or slippage of one or more plies, overfilling, fillingmaterial becoming caught in the mouth of the bag above the belts, etc.In any case the fault is corrected before any damage is done.

The preferred form of the invention is illustrated herein, but otherforms may occur to those skilled in the art, and are intended to beclaimed as my invention if within the scope of the following claims.

I claim:

1. A safety stop for a filled bag closing machine of the type havingmeans for gripping the collapsed sides of a filled bag below the openend thereof to be closed and assisting to feed the bag into suitablemechanism for effecting the closure thereof, comprising a plate having athroat of sufficient width to permit passage of a bag end therethroughas the bag is progressed by said means, a switch-controlling, rotatablymounted rod from which said plate depends, constantly tensioned springmeans tending to prevent rotation of said plate relative to said rod,

and a second spring means placed under tension by rotation of said rodwhereby the effect of said first spring means may be overcome.

2. A safety stop for a filled bag closing machine of the type havingmeans for gripping the 5' collapsed sides of a filled bag below the openend thereof tobe closed and assisting tofeed the bag into suitablemechanism for efiecting the. closure thereof, comprising a plate havinga throat of sufficient Width to permit passage of 10 a bag endtherethrough as the bag is progressed by said means, aswitch-controlling, rotatably mountedrod from which said plate depends,an abutment fixed to said rod and bearing against a face of said plate,an arm fixed to said rod, a 15 spring tensioned between said plate andsaid arm tending to prevent relative rotation of said plate and rod andholding said plate against said abutment, a lever fixed to said rod, anda second spring extending from said lever to a fixed pin, 20 said secondspring being placed under tension by rotation of said rod and plateuntil its tension overcomes the tension of said first spring.

HOWLAND F. BRIGGS.

